The N.sup.6 -substituted adenosines are of great significance due to their advantageous biological properties, e.g. as cytokinins, and as CNS-active and/or cardiac-circulation-active substances.
These compounds are generally produced by reaction with amines from the 6-halo- or 6-alkyl-mercaptopurine nucleosides, prepared in several stages from inosine and/or guanosine (W.W. Zorback and R. S. Tipson, Interscience Publ. New York [1968], pp. 210, 242, 258). Considering the large number of stages in these syntheses, the processes are expensive and complicated.